See the following articles for more information:
The CREATE MULTIPLE DICHOTOMY FROM command allows you to create a new derived Multiple Response variable by using an existing categorical array variable as input by indicating which code to use as a selected category. It can also be used on multiple input arrays to produce multiple output arrays based on the same selections.
A common usage for this command is to create a "top box" multiple response variable from a categorical array, which is illustrated below.
When using multiple inputs, you must indicate the same number of output aliases for each of the newly created multiple response variables.
- The LABELS argument allows you to indicate alternative names that the subvariables will have on the new multiple response variable. If omitted, then the same labels will be copied over.
- The COPY option allows you to copy the description or notes from the input array.
CREATE MULTIPLE DICHOTOMY FROM alias, ..., alias [LABELS "string", ..., "string"] SELECTED code|"label", ..., code|"label" AS alias, ..., alias [TITLE "string", ..., "string"] [DESCRIPTION "string", ..., "string" | COPY] [NOTES "string", ..., "string" | COPY];
The following example describes how to derive a multiple response variable from a categorical array, by selecting two of the responses pertaining to "At least weekly" on the ordinal scale (so in that sense, the example here is akin to a "top 2 box" summary).
In the following image, the categorical array has an "At least weekly" subtotal. In the subsequent multiple response, it has the same selections for each of the social media channels:
CREATE MULTIPLE DICHOTOMY FROM sns2_cat SELECTED "Several times a day", "About once a day" AS sns2_weekly TITLE "Use Internet at least weekly" DESCRIPTION COPY;
The resulting multiple response variable contains the same level of missingness as the input categorical array from which it is derived. Note that the values correspond to the "At least weekly" subtotal (e.g., 42% for Twitter):